Sains Malaysiana 38(6)(2009): 857–861

Pencirian Mikrostruktur Katod La-Sr-Co-Fe-O bagi Sel Fuel Oksida

Pepejal Bersuhu Sederhana (IT-SOFC )

(Microstructure Characterization of La-Sr-Co-Fe-O Cathode for Intermediate

Temperature Solid Oxide Fuel Cell (IT-SOFC))

Noorashrina A. Hamid, Andanastuti Muchtar, Wan Ramli Wan Daud* & Norhamidi Muhamad

Institut Sel Fuel, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor, D.E., Malaysia

Received: 14 January 2009 / Accepted: 27 April 2009

ABSTRAK

Oksida perovskit La_1-xSr_xCo_0.2Fe_0.8O_3-δ (LSCF) dengan x = 0.3-0.5 telah dihasilkan melalui kaedah sol-gel. Ia merupakan pengalir berion campuran yang sangat baik sebagai bahan katod untuk sel fuel oksida pepejal bersuhu sederhana (IT-SOFC). Serbuk yang terhasil dicirikan dengan menggunakan teknik pembelauan sinar-X (XRD) dan keputusannya menunjukkan bahawa hablur perovskit yang tulen terhasil sepenuhnya setelah dikalsin pada suhu 900^oC. Kesan suhu pensinteran ke atas pelet LSCF dikenal pasti dengan menggunakan Mikroskop Elektron Imbasan (SEM). Keputusan menunjukkan bahawa perovskit LSCF mempunyai keliangan yang optimum sebanyak 30% setelah disinter pada suhu 900 ^oC. Keliangan optimum ini membolehkan tindak balas penurunan oksigen berlaku dengan lebih mudah. Analisis FTIR yang dijalankan menunjukkan kehadiran ikatan Fe-O dalam serbuk LSCF dan tiada bendasing yang wujud dalam serbuk LSCF.

Kata kunci: Lantanum strontium kobalt ferit oksida (LSCF); pencirian mikrostruktur; suhu pensinteran; sel fuel oksida pepejal (SOFC)

ABSTRACT

Perovskite oxide La_1-xSr_xCo_0.2Fe_0.8O_3-δ (LSCF) with x = 0.3-0.5, an excellent mixed-ionic conductor that can be used as cathode material for the intermediate temperature solid oxide fuel cell (IT-SOFC) has been developed using the sol-gel method. The resulting powder was characterised using X-Ray Diffraction (XRD) which showed that pure crystals of perovskite were fully formed after calcination at 900 ^oC. The effect of sintering temperature on the microstructure was observed using Scanning Electron Microscopy (SEM) analysis. The results showed that the LSCF perovskite have the optimum porosity of 30% after sintered at 900 ^oC and thus enable the oxygen reduction occurred easily. FTIR results revealed that only Fe-O bond exists in the LSCF powder and no impurities detected.

Keywords: Lanthanum strontium cobalt ferrite (LSCF); microstructure characterisation; sintering temperature; solid oxide fuel cell (SOFC)

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*Corresponding author; email: wramli@vlsi.eng.ukm.my